Efficiency improvement of total focusing imaging based on sparse array method

Abstract

In this paper, a design concept of sparse array is applied to total focusing imaging technique. During the process, the elements of a phased array are partially selected according to the theory of effective aperture, in order to reduce the amount of captured data and shorten the processing time of TFM imaging. Simulated imaging with Field II program and experimental verification on two standard phased array specimens are performed, based on three selected arrays which are sparsely as 1/2, 1/4 and 1/8. The results compared with the full array in terms of image quality and computing efficiency, show that the computing efficiency of TFM imaging can get a rise of 40 percent by adopting the sparse array design. Meanwhile, an approximate resolution can be achieved at the lowest array sparse rate of 1/4. Affected by the side-lobes of the ultrasonic beam, contrast of the image may suffer little loss.